1. Field of the Invention
The present invention relates to a digital camera which acquires image information expressing a subject image, and stores the image information on a recording medium.
2. Description of the Related Art
In recent years, as image pickup elements, such as CCDs (Charge Coupled Devices), CMOS (Complementary Metal Oxide Semiconductor) image sensors, and the like have come to have higher resolutions and devices have been made more compact and lighter-weight, digital cameras have become more popular, and the forms in which they are used also have diversified.
The diverse forms of usage of a digital camera include, for example, cases in which the photographer aims the digital camera at himself and extends his arms and photographs so as to capture an image of himself (hereinafter, this form will be called “self-photographing”), cases in which the photographer takes a photograph while holding the digital camera up as high as possible in order to photograph a person or thing over a crowd of people, and the like.
In such forms of usage, because the photographer cannot confirm the composition by using a finder or a liquid crystal panel or the like, he must take the photograph by changing the direction of the digital camera by guessing, and must carry out re-photographing or photographing attempts many times in order to obtain photographed results of a desired composition.
In any case, because the photographer aims the digital camera with his arms extended, even if the period of time from the time when the photographer first aims the digital camera to the time when he carries out photographing is extremely short, it is difficult to maintain the angle and the position of the digital camera. In addition, because the shutter button (release) must be operated in this unstable state, it is easy for blurring due to inadvertent movement of the photographer's hands to occur.
Moreover, because the photographing distance at the time of self-photographing is short, the setting must be changed to a macro photography state depending on the type of camera. In addition, in a camera having a flash-emitting function, if the flash emits light as usual, white spots may arise. Therefore, there are cases in which it is better to prohibit the flash from emitting light.
As the forms of usage of a digital camera have become diverse in this way, techniques for supporting the photographing, such as blurring correction, automatic determination of the photographing timing, automatic changing of the setting in accordance with the photographing state, and the like, have been proposed in order to be able to photograph a subject image well regardless of the form of usage, the level of the photographing techniques of the photographer, the absence/presence of knowledge on the part of the photographer, and the like.
As a technique for automatically determining the photographing timing, there is a conventional technique (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2000-347277) in which, when photographing is instructed by the photographer, the subject is picked-up and the main subject in the picked-up image is extracted, and when main subjects extracted from plural images obtained by further image pickup satisfy a predetermined condition (i.e., carry out a predetermined movement), it is judged to be the photographing timing.
However, in the aforementioned technique disclosed in JP-A No. 2000-347277, movement of and changes in the main subject are the basis of determining the photographing timing. Therefore, after the main subject is extracted, the movement and changes of that main subject must be detected, and there is the problem that the processing for determining the photographing timing is complex.
Further, in a form of usage in which the image angle is unstable as described above, it is difficult to extract slight movements or changes of the subject. The problem arises in that the determination of the photographing timing is not carried out depending on the form of usage, and the desired image information cannot be obtained.